Transcript of More on the Selfish Gene and Evolution

I think I'm going to have some of these side videos that have some additional information that can help in understanding the main bits from the other videos. They might have some vloggy bits too, with me maybe asking more questions than I'm answering.... or just voicing an opinion and speculating. All with markedly lower production values. Kinda like this scene. Maybe I'll play the intro real fast like: Bunnana bum budum bum buh duh bunanana buh bu bu buh buna buna buna baunanana Bum So there are actually some birds with horns. Pictured here. They went unmentioned because I consider these horns to be lackluster and unimpressive. Although apparently cassowary are able kill people. They can slash you across the gut like a velociraptor and disembowel you. So if you see one, don't make fun of its horn thing. It will murder you and feel no emotion. Evolutionary theory people often talk about things only in terms of reproduction. Like: "camouflage is good because it helps reproduction". I think because reproduction is the more important thing. It's sort of a short hand for saying: "Camouflage helps survival so that the organism can go off and reproduce more." But why can't there be a creature that lives forever and maybe reproduces once every thousand years or maybe not at all. It's all about perpetuating the DNA, so could this be another "strategy"? There's kinda 2 general categories for different reproductive "strategies", K selected creatures, and r selected creatures. r selected is like your bacteria, fish, small rodents, probably most plants. Creatures that make lots of children, that most of which will likely die before adulthood, depending on the carrying capacity and what the population is. K selected is like your elephants, whales, other large mammals and... us. They make less children that tend to be born bigger and in general they get more parental care and survive better. These are just general categories that category making people make. There's lots of organisms that don't really fit the classification. And different genders can have different strategies. In mammals where there's sometimes one dominant male mating with all the females: the females are more K strategists taking care of the few children that they have. While the male is more of an r strategist, producing lots of offspring that he probably doesn't care about that much. They're called r and K strategies because of the population dynamics equation their based from. It's just which factor seems to be more important in the context of this model. There are some creatures, like certain hydras and jellyfish, that seem like they might not age. They could theoretically live forever if they didn't get eaten by something. But since no one is really at the top of the food chain, all these organisms would still need to reproduce. You need these events more of you is being made, because death by something is pretty inevitable even if you don't age. I think this is why most organism is always reproducing. Also you get diversity with each new generation that can change and adapt to new situations, since the environment is always changing. There are different theories as to WHY things age. Link to senescence Wikipedia article below. Like asexual bacteria can live forever, if you look at the from them from the perspective of the colony. That might seem like a loop hole. But we're kinda just a colony of asexual cells, with just 1 line of those cells, that are doing sex and that won't age from organism to organism. Food for thought. I've been talking about like a gene for x, or a gene for y. But you probably have something more along the lines of having a bunch of genes active in certain cells in certain parts of your body. Talking about every trait as having just a single gene that controls it is just convenience. I'm assuming that a group of genes follow the same rules that a single gene would. Otherwise it's difficult to visualize. So it won't be like "a" gene for child caring. And really it seems like some animals entire development evolved and rely on being care for while young and then caring for young later. Here's another way to think about that caring relationship while we're on it. Let's look at 2 different genes. Gene 1 codes for something that increases it's own reproduction. Like a gene for disease resistance. The other gene codes for caring for offspring. Gene 1 is helping itself, increasing the amount of children it leaves behind. And its children will have an increased chance of reproduction if they have that gene. That's why that gene continues to exist. Gene 2 helps the offspring reproduce. The time and resources that it costs that individual, means it will leave behind less offspring. it's sorta free riding off the results of gene 1 and the other genes of the organism. In other words, it has evolved relying on: that that individual WILL reproduce and pass on this gene to the children. Because it doesn't really help with the individuals reproduction itself. It helps with the child's reproduction. Since this gene is in the child, it is increasing its own reproduction. That's why that gene continues to exist. But it does rely on the other genes to get it to the child. But in general, what do you get when you have a parent who's putting a lot of energy into each of the offspring, making them bigger before birth and providing them with food and protection after birth? Well you get a K strategist. What do you get when you have a parent who's concerned with making lots of kids? You get an r strategist. Both work so whatever Also, it can't be said that a gene is good or bad for reproduction. Genes just code for proteins. How the protein interacts with the environment is what determines whether it's good or bad for reproduction. Different environment leads to different good and bad. During meiosis, the two chromosomes of a pair can kinda swap some bits of DNA, before going to different sperms or eggs. This is crossing over. This is what allows us to look at different genes on the same chromosome as being separate. They may be together for while, but over long periods of time we can look at each gene as being individual. In a previous video I talked about that two parents of half ethnicities could potentially come together and produce a child of one ethnicity. The odds of this is infinitesimally small when considering just the combination of chromosomes and sex cells. But with crossing over it basically becomes almost impossible. Although it's possible for just certain stark ethnic phenotypes of the grandparents to be expressed, like skin colour. I think it would only take a couple chromosomes to not cross over too much and come together for skin colour to be of all one ethnicity. And I think this has happened before where the father was like "oh my god, this kid can't be mine. you hussy". So there's a step in between DNA and proteins I've been skipping. For the most part, DNA codes for RNA, then its RNA that codes for proteins. RNA is basically the same as DNA except it has an R, which chemically refers to this difference here on the backbone part. Also it contains the nucleotide Uracil instead of Thymine as a coding element. But they look very similar and they basically do the same thing. Also RNA is only a single strand, and not as stable as DNA. This is probably why most creatures use DNA as their long term storage thing. But its RNA that leaves the nucleus of the cell and goes to the protein factories to code for proteins. And different RNAs have other functions too. And it's also been found that RNA can act like a protein. Such as being an enzyme. Which makes sense I think. All a protein is a long chain of amino acids that when folded and bunched, have some structure that can attract things or have other functional properties. Like maybe this area here is more electronegative or does hydrogen bonding, so that it sort of attracts and holds this things here then this other one comes in over here, and then it kinda holds them together so that they react better and more frequently. That's basically how an enzyme works... at least thats how I think it works. I'm not a microbiologist leave me alone. So RNA, as a long strand of nucleotides, folds too in such a way that maybe some parts can do a similar thing. Probably not nearly as well, there's like 22 different amino acids with all these different functional groups that make up proteins, and RNA only has 4 different nucleotides and they've only got this going on. But it's been hypothesized that the first life forms were all RNA. Like RNA acted as the information store and RNA acted as early protein like molecules that did cell stuff. That's it I guess. I hope you enjoyed this edition of side notes. I'm gonna put a big subscribe button here, it does the same thing as the other one, but maybe you'll accidentally click on this one. Because it's so big. ...more adaptive behaviours based on it all. Things without brains tend to have less involved behaviours. Things along the lines of: "if notice certain chemical, then follow certain chemical". So instead of it being a matter of: things that followed that chemical left behind more copies than things that did not follow that chemical. Things with brains can learn in one lifetime which chemicals to eat and with to leave alone. Some behaviours are inherited before birth....